package com.wc.alorithm_blue_bridge._简单题.Q4900;


import java.util.Scanner;

/**
 * @Author congege
 * 最小的或运算
 * https://www.lanqiao.cn/problems/4900/learning/?page=1&first_category_id=1
 * @Date Created in 2023/11/25-17:15
 */
public class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        long a = scan.nextLong();
        long b = scan.nextLong();
        System.out.println(a ^ b);
        scan.close();
    }
}
